The series of Ebola cases that recently ended Liberia’s respite from the virus has grown to six with the death of a woman in a Monrovia hospital, according to United Nations (UN) and media reports.

In an update yesterday, the UN Mission for Ebola Emergency Response (UNMEER) said the woman died Jul 12 on arrival at the Eternal Love Winning Africa Ebola Treatment Unit. It said she was from Paynesville in Montserrado County, which includes Monrovia and adjoins Margibi County, the site of the other five recent cases.

The patient was on the list of contacts of the other cases, UNMEER said, adding that 132 contacts are being monitored in Montserrado and Margibi counties.

According to a Reuters story today, a report sent to officials involved in Liberia’s Ebola response said the woman died a few hours after admission, indicating that surveillance of known contacts of the earlier patients had not been rigorous enough. The case raised fears that the virus may be spreading in a new area of the country, the story said.

The World Health Organization had declared Liberia Ebola-free on May 9. But that status changed when a case was reported in a 17-year-old boy in Margibi County on Jun 29, and other cases in the county followed.

The source of the recent cases has not been identified, but genetic tests last week showed that the 17-year-old boy’s virus was similar to isolates from previous cases in Liberia. That implied that the cases didn’t stem from an imported case or an animal.

In other news, yesterday’s UNMEER update said Sierra Leone authorities reported eight new Ebola cases over the weekend (Jul 11 and 12). Seven were in Western Area Urban district, and one was in Kambia district.

An inhalable experimental vaccine

In another development, researchers reported the successful test of an inhalable Ebola vaccine in monkeys, which they said raises the prospect of a vaccine that could be administered without the help of trained medical personnel.

The research, reported yesterday in the Journal of Clinical Investigation, was conducted by a team from the University of Texas Medical Branch at Galveston (UTMB) and the National Institutes of Health.

The scientists developed a vaccine called HPIV-3/EboGP, which uses a modified human parainfluenza virus type 3 (HPIV-3) as a vector to express the Ebola virus glycoprotein. In the study, the team administered aerosolized (inhalable) and liquid versions of this vaccine via the nose and mouth to different groups of rhesus macaques.

Other groups of macaques were given an intramuscular Ebola vaccine based on the Venezuelan equine encephalitis virus or a control HPIV-3 vaccine lacking the Ebola glycoprotein.

Serum and mucosal samples from the animals that received the inhalable vaccine showed high levels of Ebola-specific antibodies, which exceeded or equaled the levels in the liquid vaccine recipients, the report says. Also, the HPIV-3/EboGP vaccine induced an Ebola-specific cellular response that was greatest in the lungs and in some respects was stronger in the aerosol vaccinees. Both antibody and cellular responses were greater in the HPIV-3/EboGP groups than in the intramuscular vaccine group.

The team said one dose of the inhalable vaccine fully protected macaques that were exposed to the Ebola virus from severe disease and death. Macaques that received the liquid and intramuscular vaccines also survived.

The authors said their vaccine is the first inhalable one to be tested against Ebola or any other viral hemorrhagic fever virus. “This study demonstrates successful aerosol vaccination against a viral hemorrhagic fever for the first time,” virologist Alex Bukreyev, PhD, UTMB professor and senior author, said in a UTMB press release.?The team now hopes to launch a phase 1 trial to test the vaccine’s safety and immunogenicity in humans, according to the release.